The increasing urbanization of land has produced expansive amounts of impervious surfaces, therefore producing greater quantities of runoff as the water from weather events cannot be absorbed. This runoff may carry pollutants from the surrounding area into the water system and negatively impact the water quality. A possible solution for reducing runoff from impervious surfaces is green roofs, which can absorb and filter water. To determine a green roof’s effects on the surrounding environment, a test site was built in Cleveland, Ohio. This site contains 39 test plots that differ in combinations of plant community type (restoration or horticultural), substrate type (quasi-traditional, conventional, or movable meadow), and the presence of mycorrhizae, along with empty control plots. The movable meadows were uniquely designed to capture the rainwater passing through the soil within an inner system to be reused, whereas the other plots were designed to allow the water to pass through the system and be released. Water samples were collected from each plot and the levels of nitrate, ammonium, and phosphorous were tested. It was found that plant community type had a significant effect on the total nitrogen in the runoff (p=0.0015). Across treatments, phosphorous levels were consistently greater than the high value of 1.00 mg/L, which we believe is due to the presence of substrate and not related to the substrate type itself. This is important when addressing the potential of green roofs to cause downstream water quality issues and detract from their perceived benefits.